Inflatable lifting device and control apparatus therefor

ABSTRACT

A seating device which comprises an inflatable seat (4) and an inflating means which provides for the controlled inflation and deflation of the seat. The seat (4) comprises a chamber defined by top, bottom and side walls (12, 13) which is connected to the inflation means. The inflation means comprises a motorised fan unit (20) and a control valve (6) connected by a supply pipe (10) to the seat (4). The device is inflatable from a deflated position on the base of a support surface such as a bath to an inflated position adjacent the rim of the bath such that a person sitting thereon can easily enter or exit the bath to bathe. The device is of particular use for handicapped or elderly persons and does not require mechanical actuation means and has sufficient inflatable characteristic to enable the seat to remain in a fixed position in relation to the bath.

The present invention relates to a lifting device particularly, but notexclusively for the lifting of a person and typically an elderly, infirmor injured person such that they can move from and onto an object. Suchobjects can be any of a chair, bath or bed.

At the present time there are several mechanical devices available toaid in the lifting of a person to and from an object. However themechanical devices are necessarily bulky due to the fact that in orderto be able to safely support the weight of the person being lifted theyare required to have a relatively large base to ensure that the devicedoes not topple over upon bearing the weight of the person. The size ofthese devices therefore leads to problems with their use in areas wherespace is restricted such as in hospital wards, convalescing homes,bathrooms, bedrooms and such like. This has meant that a considerableproportion of the lifting of persons is still undertaken manually as thedevices available are either too bulky to be used or the time takenusing the devices is regarded as being excessively long.

In an attempt to reduce these problems co-pending application NoPCT/G93/01104 discloses the use of an inflatable seating device andcontrol means therefore for use in lifting and lowering a person such aslifting the person to and from a bath. The inflatable seat ismanufactured with a single chamber with walls made from a plasticsmaterial and allows inflation from a flattened position where the personcan sit in the bath to an inflated position where the person is raisedto the rim of the bath so that they can then leave the same. This seatrelies upon contact with the side walls of the bath, to add to thestability of the device. The need for stability is important as theseating area is relatively small compared to the height of the devicewhen inflated and the use of the side wall contact ensures that the sameis guided such that the raising and lowering of the person sitting onthe seat during deflation and inflation is smooth and thus the personsitting on the same feels safe. It has been found that this inflatableseat, although operable successfully when side contact walls areprovided is prone to inflate and deflate in an unsatisfactory andirregular manner when no such support walls are available or the size ofthe seating area relative to the inflated height is increased. This canlead to the person sitting on the device becoming unbalanced and thefeeling of security, which is important to persons who may be infirm andunable to support themselves, is lost. One alternative is to provide aseat comprising a number of compartments as shown in U.S. Pat. No.3,330,558. However in this type of seat each compartment isindependently adjustable so as to offer variation in pressure forcomfort purposes. This seat does not allow control of the inflation anddeflation of the seat in a balanced fashion and control relative to thepressure in the other compartments of the seat.

The aim of the present invention is to provide an inflatable seat whichcan be used to raise and lower persons sitting thereon without the needfor supporting walls to be present and to allow the device to beoperable for relatively shallow lifting operations and to provide theseat and control means therefore, in a manner which allows the personsitting thereon to be raised and lowered in a relatively smooth andbalanced fashion.

The present invention provides in a first aspect of the invention alifting means apparatus including an inflatable seat (2) for the liftingand lowering of a person sitting thereon, said inflatable seat devicecomprising at least two inflatable compartments (14) and characterisedin that the lifting means includes a flow control system (12, 13', 13"),for controlling the inflation and/or deflation of each of thecompartments (14) such that the relative rate of inflation and/ordeflation of a compartment at any one time is dependent upon thepressure fluid in that compartment and the pressure of fluid in theother compartments of the inflatable seat.

Typically the system provided for controlling the inflation and/ordeflation of each of the compartments is such that the relative rate ofinflation and/or deflation of a compartment at any one time is dependentupon the pressure in that compartment at that instant and the pressureof fluid in the other compartments of the inflatable seat.

In one feature the surfaces of the inflatable seat upon which the personsits are shaped so as to encourage the person to sit comfortably in thecentre of the seat and/or is preferably shaped such that a two stageaction is applied to the person in contact therewith so that, uponinflation, the person is lifted and then in the second stage movedforward towards a standing position.

Typically the inflatable seat device is connected to control means andan inflating device to control the inflation and deflation of thecompartments in the same. The control means include a flow valve andpreferably a control valve as disclosed in co-pending applicationPCT/GB93/01104.

In one embodiment the flow valve is connected via a connecting feed toeach of the compartments of the inflatable seat device, for example whenthe device includes two compartents the flow valve is connected to aconnecting feed to each of the compartments.

In one embodiment the valve preferably includes an inlet port throughwhich the inflating fluid enters the same, and outlets through which thefluid passes into connecting feeds and into the compartments to beinflated. Upon deflation the fluid passes from the compartments throughthe connecting feeds to exit the apparatus via at least one exitaperture.

In one embodiment each connecting feed is provided with a flow controlmeans to control the flow of fluid from the compartments duringdeflation of the device and are arranged to be fully open duringinflation but during deflation the flow control means for any onecompartment which has a high fluid pressure relative to the othercompartment acts to restrict the connecting feed thereby the amount offluid which can exit from that compartment is restricted such that thecompartment with the relatively lower pressure can release fluid at thegreater rate and the compartment with the relatively higher fluidpressure releases fluid at a lower rate until an equilibrium is reachedwith the fluid pressures in the compartments substantially level.

In a further embodiment the flow valve is preferably designed to allowthe compartment which has the highest fluid pressure at any instance toreceive the greater proportion of inflating fluid and the compartmentwith the lowest fluid pressure to receive the smaller proportion ofinflating fluid at any instant.

By providing the flow valve and associated flow control means to operateas described so the person sitting on the inflatable seat device duringinflation and deflation can be maintained in a relatively level planethereby ensuring smooth movement and a feeling of security.

In one embodiment the flow valve includes a flexible diaphragm arrangedto flex according to the pressures exerted thereon by the fluid pressurein each of the inflatable seat compartments and thereby allow control ofinflation and/or deflation of the seat compartments. Preferably the flowvalve outlets and inlets are provided with check valves to ensure thatthey can only be opened during deflation and inflation respectivelythereby preventing uncontrolled leakage of fluid.

If no check valve is provided the inlet to the flow valve is smallerthan the connecting feeds to the compartments thus created duringinflation a back pressure to cause manipulation of the proportioningdiaphragm.

In one preferred embodiment the diaphragm carries a stop valve assemblyincluding a frustoconically shaped valve stop for each of thecompartments. If two compartments are provided in the device twofrustoconical stops are provided, one on each side of the diaphragm. Inthis arrangement the valve stops move with the diaphragm towards one orother of the side walls of the valve depending upon the relativepressure of the fluid in the compartments to which they are connected.The valve stops are also arranged to be linearly movable in relation tothe exit apertures in the side walls such that as the valve stops moveto or away from the side walls of the flow valve so they selectivelyincrease or reduce the amount of fluid which can escape through therespective exit aperture.

Typically the inflating fluid is air provided in a pressurised form bymeans of a blower unit connected to the flow valve via a control valveand the blower and control valve can be mounted adjacent the inflatableseat device to allow control of the same by the person sitting on theseat.

In one embodiment the compartments of the inflatable seat areinterconnected to allow limited and controlled transfer of fluid betweenthe compartments.

In a further aspect of the invention there is provided an inflatableseat comprising at least two inflatable compartments, said compartmentsseparated by an inner wall. Each compartment is preferably independentlyinflatable. In one embodiment passages may be provided between thecompartments to allow controlled and limited transfer of fluid betweenthe same. Preferably the inflatable seat is made from a flexibleplastics material which allows movement of the seat from the inflated tothe deflated position but may, in one embodiment, be provided with asupporting framework. In a yet further feature the rear of the surfaceupon which the person sits is higher than the front thereby allowing atwo stage action on the person during inflation such that the firststage is a conventional lifting action and the second stage is a pushingaction from the rear higher surface to push the person up and forwardtowards a standing position.

In a yet further aspect of the invention there is provided a liftingmeans for a person, said lifting means comprising an inflatable seat forthe lifting and lowering of a person sitting thereon and said seatprovided with associated members including support arms which can beused to provide support for the person sitting on said seat.

Preferably said support arms are provided to be movable between aretracted position when the inflatable seat is in a deflated conditionand an extended position when the seat is inflated and, in each positionprovide support for the person sitting on said seat.

Typically the support arms are connected to the seat and arranged to bemovable with the seat as it moves between inflated and deflatedconditions.

In one embodiment the seat further includes a frame for contacting asurface and providing additional stability and/or mobility and saidframe can be adjustable to allow the same to be fitted to, and used in,existing chairs.

Typically the inflatable seat comprises at least two compartments, theinflation and/or deflation of which is controlled by a flow valve andcontrol valve connected to a blower unit, by a pipe.

Specific embodiments of the invention will now be described withreference to the accompanying drawings wherein;

FIG. 1 illustrates a perspective view of the apparatus of the inventionin a first embodiment and in use;

FIGS. 2A and 2B illustrate in diagrammatic form the flow valve ininflating and deflating positions respectively;

FIG. 3 illustrates a perspective view of the flow valve in oneembodiment;

FIG. 4 illustrates the valve of FIG. 3 in cross section along line A--A;

FIG. 5 illustrates the valve of FIGS. 3 and 4 in plan;

FIG. 6 illustrates the flatable seat of the device in one embodiment;

FIG. 7 illustrates a second embodiment of the flow valve in elevation;

FIGS. 8A and 8B illustrate a detail of the flow valve of FIG. 7;

FIG. 9 illustrates a perspective view of a further embodiment of theinflatable seat device;

FIG. 10 illustrates an embodiment of the lifting means according to theinvention with the inflatable seat in an inflated condition;

FIG. 11 illustrates an embodiment of the lifting means of FIG. 10 in adeflated condition;

FIG. 12 illustrates part of the frame of the lifting means of FIGS. 10and 11; and

FIGS. 13A and 13B illustrate an alternative embodiment of lifting meanssupports.

Referring firstly to FIG. 1 there is shown the lifting means apparatusof the invention in one embodiment. The apparatus comprises aninflatable seat 2 to which is connected a fluid supply pipe 4 whichconnects the seat device 2 to a fluid blower unit 6 and for the purposeof the description the fluid is air. The blower unit is electricallypowered and can be mounted as shown an the chair 8, upon which theinflatable seat 2 is to be used. At a position intermediate the airblower unit and the inflatable seat 2 on the air supply pipe 4 there isprovided a control valve 10 which is manually operable by the user ofthe apparatus to cause any of deflation, inflation and maintainedcondition of the inflatable seat. This control valve is described inmore detail in co-pending application No PCT/GB93/01104 and acts inconjunction with the air blower unit to provide the required control ofthe supply of fluid to the seat 2. Also provided on the air supply pipe4 at the interface between the pipe and the inflatable seat 2 is a flowvalve 12 connected via connecting feeds 11', 11" to the seatcompartments 14. This valve serves to connect each of the compartments14 in the inflatable seat device 2 to the air supply pipe 4. Referringnow to FIGS. 2A and 2B an embodiment of the flow valve is shown in moredetail wherein flow control means 13', 13", are provided with one ofeach on the connecting feeds, 11', 11". The flow control means act toallow control of the deflation of each compartment relative to the othercompartments and to the differential in the pressure of air between eachof the compartments, caused, for example, by the person on the seatsitting more heavily on one compartment than the other. The provision ofthe flow valve therefore allows the inflation and deflation of thecompartments to be controlled.

The relationship between the flow valve 12, the connecting feeds 11',11", flow control means 13', 13" and the compartments 14 when ininflating and deflating positions in this embodiment is such that thevalve 12 is connected to a two compartment inflatable seat 2 and thevalve 12 is provided with two connecting feeds 11', 11" which connectthe inlet port 18, through which air from the air supply pipe 4 enters,with the compartments 14 via the flow control means 13', 13". The flowvalve 12 includes a flexible diaphragm 20 which is mounted to flexaccording to the pressure of air acting thereon and also includes atleast one, one way air exit aperture 22 through which air exits to allowdeflation.

FIGS. 3, 4 and 5 all illustrate various views of a first embodiment of aflow valve 12 wherein the inlet 18 and connecting feeds 11', 11" areshown. Also shown in FIG. 4 is the exit aperture 22. The exit aperture22 is normally sealed to prevent the ingress of air through thisuncontrolled route during inflation and is sealed by the provision of asealing band 24. The band is provided with a degree of elasticity suchthat when the control valve is set to the deflation position and theinlet 18 of the flow valve closed and deflation commences, the pressureof air which is attempting to escape the valve is sufficient to blow theband away from the exit aperture 22 to an extent to allow the fluid toescape the device and deflation to occur.

In construction, the flow valve 12 is formed of two halves 12a and 12bas shown in FIG. 5. The flexible diaphragm 20 is held in positionbetween the two halves such that the same can not be released from itsposition integral with the halves. The diaphragm also splits the inlet18 and the air entering the valve into two paths, a first path directedto a first compartment and a second path directed to a secondcompartment of the inflatable seat. As the pressure of air in each pathalters according to the pressure in the compartment so the size of eachpath and the amount of air which can pass there through is altered bythe flexing of the diaphragm away from the path and compartment whichhas the higher pressure. During inflation this deflection allows thehigher pressure compartment to be supplied with a greater amount of airthan the other thereby increasing the inflation of that compartment toraise it toward the level of the other and thereby alter the position ofthe person thereon an equilibrium position. When no check valve isprovided the dimensions of the inlet 18 are smaller than each connectingfeed 11', 11" thereby providing unequal back pressure on each side ofthe diaphragm which is proportional to the variation in pressure betweenthe compartments and this allows the system to operate effectively.

FIG. 6 illustrates the inflatable seat device 2 in one embodiment of theinvention which is seen to comprise two compartments 14. The provisionof an inflatable seat device having more than one compartment allows theseat to be more easily controlled and allows the seat to be more stableduring inflation. However, when the device is in use during inflation ordeflation the pressure on the air in one of the compartments can begreater than in the other due to the person being lifted or loweredsitting more heavily on one compartment than the other. This wouldnormally lead to the person tilting and lead to feelings of insecurity.The apparatus of the invention prevents this from happening.

When inflation has occurred the control valve is moved to a positionwhereby the fluid is held in the compartments of the device and hencethe person sitting thereon is maintained in a raised position until thecontrol valve is again altered.

In FIGS. 9, 10, 13A and 13B illustrated alternative embodiments of theseat 102, 202 wherein the surfaces 121 of the compartments 14 upon whichthe person sits are shaped to encourage the person to sit comfortably onthe centre of the seat and thereby encourage even distribution ofweight. Furthermore the compartments are shaped such that the rear ofthe seat area upon which the person sits is significantly higher andthereby forms upstanding portions 103, 203. In use and for exampleduring inflation of the seat the provision of the upstanding portionallows a two stage action, the first being a lifting action on theperson and the second being a pushing forward action to encourage theperson to move toward a standing position.

FIGS. 10-12 and 13A and B illustrate embodiments of the lifting meanswherein the inflatable seat is provided with associated support armswhich can be used to provide support to the person sitting on the seat.In FIGS. 10 and 11 a frame 30 is provided which locates the inflatableseat 2 in position and provided with support legs 32. The frame isadjustable as shown in FIG. 12 to allow the same to be retrofitted toexisting chairs.

In FIGS. 10 and 11 the support arms 34 of the frame 30 are shown to bepivotally movable as the seat 2 moves from an inflated position as shownin FIG. 10 to a deflated position as shown in FIG. 11 thereby providingsupport for the person thereon in inflated and deflated positions.

In FIGS. 13A and 13B there is shown an alternative embodiment whereinthe inflatable seat 2 is provided with attached support arms 40 integraltherewith. The support arms 40 are hingedly connected to the seat so asto be movable to the desired support positions when the seat is in aninflated position as shown in FIG. 13A and deflated position as shown inFIG. 13B. The support arms 40 can also include inflatable compartmentsif required which, typically are interconnected to compartments of theinflatable seat.

In using the embodiments of the invention herein described and duringinflation the control valve 10 allows air supplied from the blower unit6 to pass through the flow valve 12 and enter the compartments 14 of theinflatable seat device 2 via the connecting feeds 11', 11" and flowcontrol means 13', 13" which remain fully open during inflation. If aperson is sitting on one compartment more than the other then thepressure of air in the compartment which is being sat upon more isgreater. This higher pressure causes the compartment to "flatten" andhence the person would be raised on a tilted plane. However, when thispressure differential occurs in the apparatus of the current inventionthe differential is detected by the diaphragm 20 in the flow valve 12 asshown in FIG. 2A. This detection causes the diaphragm 20 to flex to aposition as shown in FIG. 2A such that the majority of air entering thevalve through the inlet 18 is directed toward the high pressurecompartment 14A which has air at the higher pressure and less air isdirected toward the compartment 14B. Thus the increase in air supply tocompartment 14A relative to compartment 14B is sufficient to allowcompartment 14A to be filled at a quicker rate and thereby raise thecompartment more quickly to return the seat to an equilibrium positionsuch that the person sitting on the same is maintained in asubstantially horizontal plane. If, during inflation, the person sittingon the device alters their position such that the relative pressures ofthe air in the compartments alter so that, for example, the air incompartment 14B has a greater pressure, the diaphragm 20 is caused toflex in the other direction by the change of back pressures of the fluidon either side of the diaphragm in the valve and thus the supply of airto compartment 14A is reduced and increasing the flow of air tocompartment 14B. Thus the current invention provides a system wherebythe inflation of the compartments of the inflatable seat device duringinflation can be controlled to keep the person sitting on the device ina substantially level plane despite their position on the same or anychange of position which they may make during inflation.

During deflation and referring to the embodiment shown in FIGS. 3-5 thediaphragm is not utilised as venting of the fluid is effected by thefluid exiting the compartments 14 into the connecting feeds 11', 11".The flow control means 13', 13' in the feeds are provided such that ifthe compartment to which each flow control means is connected is underhigher pressure the flow control means acts to restrict the connectingfeed from that compartment and hence restricts the flow of air from thatcompartment. The restriction of fluid flow decreases the rate ofdeflation of the compartment relative to the flow of air from the othercompartment and hence the two compartments are brought into equilibriumsuch that a person sitting on the compartments during deflation isbrought back into a substantially horizontal plane. Once the pressure inone particular compartment reduces so the flow control valve opens morefully. The fluid exiting the compartments passes through the connectingfeeds 11', 11" to exit the device via the exit aperture 22 in the flowvalve as the check valve 10 is closed during deflation.

Referring now to the embodiment of flow valve illustrated in FIGS. 7, 8Aand 8B the flow valve again comprises a diaphragm 120 which is arrangedto flex dependent on the pressure of air acting on each side thereof.The flow valve is provided with an inlet 118 controlled by a check valve110 which allows air to pass therethrough upon inflation but closes thesame upon deflation where the air exits via aperture outlets 122 whichare normally closed by a band 124. In this embodiment the diaphragmcarries two frustoconical valve stops 150 which are arranged to liewithin the exit aperture outlets 122 such that movement of the diaphragm120 is indicated in the directions of arrows 152 causes thefrustoconical valve stops to move. In FIG. 8A the valve is shown in acondition where the pressures in both compartments which are connectedto the sides 118A and 118B of the valve passage have equal pressures andtherefore the diaphragm 120 is not flexed and the air can exit througheach of the annular spaces 154 and 156 defined between the valve stops150 and apertures 122. In the example shown in FIG. 8B, there is ahigher fluid pressure in the compartment connected to side 118A dueperhaps to the person sitting more heavily on that particularcompartment and this higher pressure flexes the diaphragm 120 towardsthe side 118B which is connected to the compartment with the lowerpressure. Hence, with this movement of the diaphragm, one of the valvestops 150 is moved to increase the size of the annular space 154 definedbetween the valve stop 150 and one aperture 122 through which air canpass and the movement also causes the other of the frustoconical valvestops 150 to reduce the size of the annular space 156 defined betweenthis stop 150 and the other aperture 122 and hence more air can escapefrom the lower pressure compartment connected to side 118B than from thehigher pressure compartment connected to side 118A and this conditiontherefore brings the lower pressure compartment which will be higherthan the higher pressure compartment towards an equilibrium whereuponthe diaphragm will return to the position as shown in FIG. 8A or indeedmay be caused to flex in the other direction as appropriate. Thisprocess can therefore be repeated in both directions 152 during thedeflation of the seat and helps to maintain the person in asubstantially horizontal plane. In this arrangement no other outlet flowcontrol means are provided.

Upon inflation, the diaphragm 120 which is mounted along the length ofthe valve 112 and which carries the frustoconical valve stops 150, movesto one side or the other of the valve depending on the relative pressureof the compartments 114 of the seat 102. During inflation, and as withthe flow valve 12 of FIGS. 3-5, if the pressure of one compartment ishigher than the other then more air will be provided to the compartmentwith the higher pressure to inflate that compartment more quickly thanthe compartment with the lower pressure thereby bringing the personsitting on the same into a more level position and the position of thediaphragm changes as the relative pressures in the compartments change.

Upon deflation the check valve 110 is held in a closed condition andtherefore no air can pass through the same and can only escape throughthe outlets 122 The diaphragm 120 and frustoconical stops 150 operate toensure that if one of the compartments has a higher pressure of air thenthis deflates more slowly than the other compartment so that the othercompartment deflates more quickly thus drawing the weight of that persononto the lower pressure compartment to bring the person sitting thereoninto a level plane. This is achieved by the movement of thefrustoconical stops 150 in conjunction with the outlets 122 to controlthe volume of air which can pass through each of the outlets 122 byaltering the size of the annular spaces 154, 156. The frustoconicalstops 150 are arranged in relation to the outlets 122 so that an amountof air can pass through each of the outlets at all times and thisreduces the "hunting" effect which can occur if there is too substantiala change between the pressure differential in the compartments and thesystem is too sensitive. The amount of air which can pass through theoutlets 122 is determined by the position of each of the frustoconicalstops 150 relative to the respective outlets 122. The position of thesame is determined by the movement of the diaphragm upon which they aremounted such that the side of the diaphragm relating to the relativelyhigh pressure compartment is moved away from the side wall of the valvewhich in turn moves the frustoconical shaped part on the opposite sideof the diaphragm into the outlet 122 to increase the annular space and,as the annular space of the outlet is increased due to the shape of thevalve stop, so more air can escape therethrough and so more air isreleased from the compartment with the relatively low pressure than ispossible from the compartment with the relatively high pressure. Themovement also causes the wider part of the other frustoconical stopvalve 150 on the side of the diaphragm relating to the high pressurecompartment to move to restrict the annular space on that side torestrict the escape of the air through the other outlet 122. Thisdiaphragm condition changes as pressure of air in the respectivecompartments changes and thus control of the release of the air duringdeflation is achieved.

The fluid used to inflate the device is referred to as air but it shouldbe noted that the control apparatus and the principles of the same asset forth herein are equally applicable to whichever fluid is desired tobe used for the purpose of inflating the compartments.

Thus the present invention provides a lifting device which comprises aninflatable seat which is formed from more than one compartment andwhich, when inflated or deflated causes the person sitting thereon to beraised or lowered accordingly. The provision of the control apparatusand particularly the flow valve ensures that during the inflation and/ordeflation of the seat, differentials in the pressure of the fluidbetween the compartments is taken into account and the valveautomatically adjusts to control the amount of fluid entering or leavingeach compartment to bring the pressures in each compartment to adjustthe rate of lift or lower and thereby maintain the person thereon in asafe, secure and balanced position during inflation and deflation.

I claim:
 1. A lifting means apparatus comprising:an inflatable seathaving means for the lifting and lowering of a person between standingand sitting positions thereon, said inflatable seat comprising at leasttwo inflatable compartments; and the lifting means includes a flowcontrol means for controlling the inflation and/or deflation of each ofthe compartments as the seat moves between substantially deflated andinflated conditions such that the relative rate of inflation and/ordeflation of a compartment at any one time is dependent upon thepressure, fluid in that compartment and the pressure of fluid in theother compartments of the inflatable seat, as the seat moves betweendeflated and inflated conditions and the person thereon moves betweenstanding and sitting positions.
 2. A lifting means according to claim 1wherein the inflatable seat upon which a person sits includes means formoving the person in two stages such that during inflation the person islifted in a first stage and in a second stage is pushed forwards towardsa standing position.
 3. A lifting means according to claim 1 wherein theinflatable seat device is connected to a fluid supply pipe which in turnis connected to a fluid supply.
 4. A lifting means according to claim 3wherein intermediate the fluid supply and the inflatable seat there isprovided a control valve to control the fluid supply and a flow valvehaving means to control the inflation and/or deflation of thecompartments of the inflatable seat.
 5. A lifting means according toclaim 4 wherein the flow valve includes an inlet port to which inflatingfluid enters the same, outlets through which the fluid passes into andfrom connecting feeds to the compartments of the inflatable seat and atleast one exit aperture through which fluid exits the valve upondeflation of the inflatable seat.
 6. A lifting means according to claim5 wherein each connecting feed is provided with a flow control meansduring deflation, said flow control means arranged to be fully openduring inflation, but, during deflation, the flow control means areprovided to selectively restrict the connecting feeds according to therelative pressures of the compartments of the inflatable seat.
 7. Alifting means according to claim 4 wherein the flow valve is providedwith an adjustable means such that during inflation and/or deflation ofthe inflatable seat, the said adjustable means is acted upon by therelative pressures of the fluid in the compartments of the inflatableseat to adjust the proportion of the fluid which is supplied to and/orexits from each of the compartments dependent upon the pressuredifferentials of the fluid in the compartments of the seat.
 8. A liftingmeans according to claim 7 wherein the adjustable means is a flexiblediaphragm which is acted upon by the pressure of fluid in each of thecompartments.
 9. A lifting means according to claim 8 wherein thediaphragm carries a stop valve assembly including a valve stop for eachof the compartments of the inflatable seat.
 10. A lifting meansaccording to claim 9 wherein the valve stops are frustoconically shapedand arranged on the diaphragm in relation to the exit apertures of theflow valve to allow control of deflation.
 11. A lifting means accordingto claim 10 wherein the valve stops are provided to be linearly movablein relation to the exit apertures of the flow valve such that as eachvalve stop moves to or away from the respective exit apertures of theflow valve so they selectively increase or restrict the amount of fluidwhich can escape through the respective exit apertures.
 12. A liftingmeans according to claim 4 wherein the inlet of the flow valve isprovided with a check valve which is closed during deflation and theexit aperture is provided with means to close the same during inflationthereby preventing uncontrolled leakage of fluid from the valve duringinflation and deflation.
 13. A lifting means according to claim 3wherein the supply pipe is connected to the inflatable seat via a flowvalve which is connected via connecting feed to each of the compartmentsof the inflatable seat.
 14. A lifting means according to claim 1 whereinthe inflating fluid is provided in a pressurised form by means of afluid supply in the form of a blower unit.
 15. A lifting means accordingto claim 1 including means for interconnecting the compartments to allowlimited and controlled transfer of fluid between the compartments.
 16. Alifting means according to claim 1 wherein said at least two inflatablecompartments are separated by an inner wall such that each compartmentis independently inflatable and/or deflatable by said flow controlmeans; said flow control means including means for selecting andregulating the supply and escape of fluid to and from the compartmentsto inflate and deflate the compartments.
 17. A lifting means accordingto claim 16, including means for linking the compartments to allowcontrolled and limited transfer of fluid between the compartments.
 18. Alifting means according to claim 16 wherein the seat is formed from aflexible plastics material to allow movement of the seat from theinflated to the deflated position.
 19. A lifting means according toclaim 16 wherein the surface on which the person sits is shaped suchthat there is provided a rear, upstanding section which allows the seatduring inflation to exert a lifting action on the person and a pushingforward action to move the person toward a standing position.
 20. Alifting means according to claim 16 wherein said inflatable seatincludes support arms which can be used to provide support for theperson sitting on said seat.
 21. A lifting means according to claim 20wherein the support arms provided to be movable relative to theinflatable seat between a retracted position when the inflatable seat isin a deflated condition and an extended position away from the seat whenthe seat is inflated to provide support for the person sitting on saidseat.
 22. A lifting means according to claim 21 wherein the support armsare connected to the seat and arranged to be movable with the seat as itmoves between inflated and deflated conditions.
 23. A lifting meansaccording to claim 16 wherein the device further includes a frame forcontacting a surface and providing additional stability and/or mobility.